All I see is just the file name and line number, as highlighted in the screenshot above. Activating the link shows a dialog box with the information: »Cannot open source files: no scripts to do so are currently loaded. Refer to the Lokalize handbook for script examples and how to plug them into your project.«

However, after reading this, I'm as smart as before - this software's design is downright hostile. Exactly what do I have to copy where to make this work?

Alternatively, recommend a PO editor that is confirmed to have this feature I need. PO files for testing are available.